Takayasu arteritis - Skin
No definitive cause of Takayasu arteritis has been identified, but it is thought to be an IgG-mediated autoimmune vasculitis, perhaps triggered by a cross-reacting infectious agent.
The disease typically presents in the second and third decade of life in females (10:1) of Asian descent. It is most prevalent in Japan, Southeast Asia, India, and Mexico but has been found worldwide and in both sexes. Incidence is ~2.5 per million.
The disease has two phases that may overlap: a "pre-pulseless" and a pulseless phase. In the first phase, a constellation of nonspecific constitutional symptoms and signs including fever, night sweats, malaise, weight loss, arthralgia, myalgia, and mild anemia may be seen. In the second phase, the characteristic sequelae of large-vessel stenosis – upper extremity claudication, diminished brachial pulses, and/or differences in blood pressure between contralateral or ipsilateral extremities – occur.
For diagnosis, the American College of Rheumatology requires 3 of 6 criteria:
- Age at disease onset ≤ 40 years
- Claudication of extremities
- Decreased brachial artery pulse
- Blood pressure difference of > 10 mmHg between arms
- Bruit over subclavian artery or aorta
- Arteriogram abnormality
Diagnosis during the pre-pulseless phase is difficult because of the nonspecific nature of symptoms and lab abnormalities. Diagnosis is usually made during the pulseless phase when clinical criteria, as per above, are met. Angiography is essential to confirm diagnosis.
Constitutional symptoms are typically intermittent, and vascular complications are generally progressive, but the prognosis is generally good, with 5-year survival reports of 90% to 94%.
Pediatric Patient Considerations:
Takayasu arteritis in children rarely presents with pulselessness, claudication, or bruits. It is most frequently identified during evaluation for hypertension, heart failure, and neurological symptoms.
For more information, see OMIM.
M31.4 – Aortic arch syndrome [Takayasu]
- Giant cell arteritis (see polymyalgia rheumatica) – typically seen in older patients (mean age 72), rarely causes hypertension, claudication, or bruits; ocular involvement is common
- Sarcoidosis – look for peri-hilar lymphadenopathy and pulmonary granulomas
- Behçet's disease – look for aphthous ulcers
- Buerger's disease – look for digital ulcers and ischemic changes in a patient with a history of tobacco use
- Sweet's syndrome
- Mycotic aneurism – rule out sepsis or endocarditis with blood culture
- Tuberculosis – check PPD status
- Tertiary syphilis – check for fluorescent treponemal antibody (~ 1/4 of RPR is false negative in tertiary syphilis)
- Leprosy – look for hypopigmented or erythematous macules with loss of sensation, thickened peripheral nerves, and acid-fast bacilli on skin smear or biopsy
- Congenital malformation – aortic coarctation or middle aortic syndrome; unlikely to have constitutional symptoms
- Marfan syndrome – look for arachnodactyly, pectus excavatum or carinatum, and arm span greater than height; family history
- Neurofibromatosis – look for neurofibromas, café au lait spots, ocular Lisch nodules; family history (autosomal dominant)
- Ehlers-Danlos syndrome – look for fragile skin, easy bruising, joint hyperextendability, frequent dislocations
- Fibromuscular dysplasia – look for "string of beads" with angiography; family history (autosomal dominant)
- Post-radiation therapy – may cause large-vessel stenosis
- Atherosclerosis – check lipid panel
On average it takes 44 months from onset of symptoms to diagnose Takayasu arteritis. Because of its rarity and the often subtle physical findings, Takayasu arteritis frequently fails to enter the differential diagnosis for patients with fever of unknown origin (FUO). Thus it is critical to consider Takayasu arteritis in patients under 40 with FUO, aortic regurgitation, hypertension, or absent pulses. Rarely, patients older than 40 years of age meet the criteria for Takayasu arteritis because of a prolonged pre-diagnostic period or late onset of symptoms. In this case, giant cell arteritis may be indistinguishable from Takayasu arteritis; however, initial treatment for both is nearly identical.